Urban Change Research Articles

The Risk of Virus Emergence in South America: A Subtle Balance Between Increasingly Favorable Conditions and a Protective Environment.

South American ecosystems host astonishing biodiversity, with potentially great richness in viruses. However, these ecosystems have not yet been the source of any widespread, epidemic viruses. Here we explore a set of putative causes that may explain this apparent paradox. We discuss that human presence in South America is recent, beginning around 14,000years ago; that few domestications of native species have occurred; and that successive immigration events associated with Old World virus introductions reduced the likelihood of spillovers and adaptation of local viruses into humans. Also, the diversity and ecological characteristics of vertebrate hosts might serve as protective factors. Moreover, although forest areas remained well preserved until recently, current brutal, sudden, and large-scale clear cuts through the forest have resulted in nearly no ecotones, which are essential for creating an adaptive gradient of microbes, hosts, and vectors. This may be temporarily preventing virus emergence. Nevertheless, the mid-term effect of such drastic changes in habitats and landscapes, coupled with explosive urbanization and climate changes, must not be overlooked by health authorities.

Gi’iko Ce:mo’oidag: A proposal for urban-agrarian development in the Gila River Indian Community, Arizona

The urban fabric of the Phoenix Metropolitan Area (PMA) is becoming inhospitable. Contributing factors are: low population density, dependence on automobiles and air conditioning, Urban Heat Island effect, uncertain water supply, lack of sustainable policies, and low community connectivity. Failing to adapt could spell the end of the PMA’s life cycle. This paper highlights the Indigenous Akimel O’Otham as key agents of sustainable change in this region, on account of their espousal of sustainable values; and their water rights reclamation allocating resources for agricultural development, of which the tribe has already undertaken the Pima-Maricopa Irrigation Project (P-MIP). The design presented offers a possible avenue for the tribe to complement P-MIP’s ambitions with urban-agrarian development, diversifying the uses of their water supply. The proposal is accompanied by a speculative financial plan to ensure their independence from external investment. This could contribute to fostering urban change and promoting a more resilient future.

Urban land use simulation and carbon-related driving factors analysis based on RF-CA in Shanghai, China

As global climate change intensifies, climate protection is important for the sustainable development of human society. In the process of urbanization and industrialization, carbon dioxide emissions are an important factor contributing to global warming. Therefore, modelling projections of future urban land use under low-carbon scenarios are essential for sustainability policy development. Few studies have focused on the impact of carbon emissions on urban land use change in Shanghai, as current research has primarily concentrated on developing methods for urban land use modelling. This paper utilizes a cellular automata (CA) simulation model based on the Random Forest (RF) algorithm to select various spatial variables of carbon emissions as the driving factors that affect urban land use changes. These variables include traffic location factors, economic development factors, electricity consumption, and population density. In this study, remote sensing imagery of urban nighttime lighting is also used to construct a simulation model of land use types in Shanghai. The model is then used to analyze the contribution of carbon emission constraints to urban land use changes. Actual historical land use data from 2013 and 2019 are used for validation, and the prediction model is used to predict land use outcomes under different low-carbon scenarios in 2025. The model is validated by simulating multiple intra-city land use maps for 2019 (kappa = 0.88, OA=92.71 %). The method of out-of-bag error from the random forest is used to evaluate the significance of carbon emission constraints. Using the validated model, the constraints in the CA model are changed to predict the land use simulation results of Shanghai in 2025 under different low-carbon scenarios. In terms of significance, factors such as distance to power plants, distance to major roads, real GDP, and population density can all have a significant impact on changes in urban land use. By selecting the low-carbon scenario with the most appropriate thresholds for each driver, it is possible to obtain the land use simulation results of Shanghai in 2025 under the optimal low-carbon scenario, while ensuring the high accuracy of the RF-CA model and simultaneously reducing the impact of factors on the city’s overall carbon emissions. This paper provides a scientific base for urban planners and scholars to thoughtfully design urban land use while cutting down on carbon emissions. Furthermore, it can aid government agencies in establishing associated planning approaches.

Institutional Designs for Procedural Justice and Inclusion in Urban Climate Change Adaptation

Although there is broad consensus that more inclusive approaches are needed in climate adaptation planning, it is unclear how cities should redesign rules, institutions, and decision-making processes to produce more equitable forms of participation and engagement. This paper evaluates different planning procedures and institutional arrangements across twenty-five U.S. cities. Although arrangements are context-specific, institutional designs fall into three categories: consultative partnerships, strategic collaborations, and expansive co-governance arrangements. Each institutional design leads to different kinds of inclusion outcomes. Our results empiricize how cities can pursue more inclusive climate adaptation planning and highlight opportunities to advance and implement broader procedural equity goals.

Population at risk of dengue virus transmission has increased due to coupled climate factors and population growth

Dengue virus transmission has increased over the last four decades seemingly due to changes in climate, urbanization and population growth. Using estimates of dengue transmission suitability based on historical temperature and humidity data, we examined how shifts in these climatic variables and human population growth have contributed to the change in the geographical distribution and size of the global population living in areas with high climate suitability from 1979 to 2022. We found an expansion in climate suitability in North America, East Asia and the Mediterranean basin, where with few exceptions, endemicity is not yet established. Globally, we estimated that the population in areas with high climate suitability has grown by approximately 2.5 billion. In the Global South, this increase was largely driven by population growth in areas with historically favorable climate suitability, while in the Global North this increase predominantly occurred in previously unfavorable areas with limited population growth.

Preliminary Evaluation of the Effect of Domestication on the Marketable and Nutritional Quality of B. aegyptiaca (L.) Delile Oil from Algeria.

Balanites aegyptiaca is a multipurpose fruit tree that grows wild in many arid and semi-arid African areas; however, recent domestication efforts have been undertaken to protect the species from the threat of urbanization and climate change. Within this context, the impact of the domestication of Algerian B. aegyptiaca was evaluated on its seed oil, which is already valued as food. Hence, oils from wild and domesticated trees were comparatively investigated for their physicochemical and compositional quality. Both oil types had a good oxidative stability and met the requirements for human consumption in terms of the saponification index, the free acidity, and the peroxide value. Moreover, they showed a comparable FA composition, with high levels of oleic and linoleic acids, which are beneficial for the consumer's health. Domestication led to a statistically significant decrease in the tocopherols and polyphenols in the oil. The phytosterols and squalene were slightly lower in the domesticated oil than in the wild relative, although no statistically significant differences were observed. A comparable mineral profile was revealed and the minimal variations in the trace elements between the oils could be related to the natural variability in the seeds. Hopefully, this study will encourage the domestication of B. aegyptiaca as a sustainable strategy for enhancing its socioeconomic value in Algerian rural areas.

The Impact of Population Shrinkage on Economic Resilience in Mountain Cities: A Case Study of Guizhou Province, China

With the recent changes in population structure and continuous urbanization, the degree of population shrinkage in mountain cities has increased, especially under the impact of the COVID-19 epidemic, and the economic development of such mountain cities has become a prominent issue. The epidemic has not only exposed the vulnerability of these cities to economic development but also aggravated the negative impact of population contraction, bringing about new challenges and pressures related to regional population development and economic resilience. This change has become an important topic in the study of mountain cities. Therefore, taking Guizhou Province as a case study, this work applies the population change rate, the entropy method, and a mediation effect model to study the spatiotemporal evolution of population shrinkage and economic resilience, and it explores how population shrinkage influences economic resilience. The results reveal the following: (1) Few counties experienced population shrinkage in Guizhou Province from 2013 to 2017, indicating a sporadic distribution pattern, whereas the degree of population shrinkage increased rapidly from 2018 to 2022, revealing an east–west symmetrical distribution pattern, with Guiyang city located on the central axis. (2) There are significant regional differences in the spatial distribution of the level of economic resilience between the two periods. Under the impact of COVID-19, from 2019 to 2022, although the overall level of economic resilience increased, the level of resilience in most counties tended to decrease. (3) Regarding the mediating effect, population shrinkage affected the level of economic resilience through general public budget expenditure, foreign trade investment, new urban employment, and GDP. The abovementioned findings are helpful for providing theoretical support and empirical guidance for the sustainable development of mountain cities in the face of population contraction, economic challenges, and promoting regional coordination.

Use of Geographic Information Systems to Analyze the Distribution of Water Catchment Areas in Ambon City, Indonesia

Background: Ambon City, as the capital of Maluku province, faces serious challenges in water resources management due to rapid urbanization and climate change that affects rainfall patterns. This study aims to analyze the distribution of water catchment areas using Geographic Information Systems. Methods: This study used variables of rainfall, soil type, land use, and slope which were analyzed using Geographic Information System (GIS) approach with overlay technique. Findings: The results showed that the water catchment area in Ambon City with a rather critical condition has an area of 2,350.27 ha, good condition of 13,524.39 ha, starting critical condition of 2,827.62 ha, normal natural condition of 13,636.20 ha and very critical condition of 236.12 ha. This research shows that soil characteristics, land use, slope, and rainfall in Ambon City have a significant influence on the capacity of water catchment areas. Findings from analysis using Geographic Information Systems (GIS) show that soil type, land use, and slope have a significant effect on water infiltration capacity, with alluvial soils having the best infiltration capacity. Conclusion: The results of this study emphasize the need for better management and strict implementation of spatial policies to protect water catchment areas, in order to reduce disaster risk and support sustainable development in Ambon City.

Impacts of River Network Connectivity on Flood Signatures and Severity Regulated by Flood Control Projects

The operation of hydraulic projects within plain river networks to mitigate floods can alter river network connectivity patterns, subsequently affecting flood processes. This study employed the MIKE 11 model to simulate flood processes under three different river network connectivity scenarios. Based on the simulations, we propose a method to evaluate flood intensity severity by integrating three flood characteristic indices: Slope of the Flow Duration Curve (SFDC), Rising Climb Index (RCI), and Flashiness Index (FI). These indices assess the overall magnitude of change, the rate of rise, and process fluctuations, respectively. Results indicate that changes in river network connectivity significantly impact RCI and SFDC, more than FI. Compared to the natural river network connectivity mode, changes in urban or watershed river network connectivity resulted in a significant decrease in RCI values by 3–37% or 18–38% across various return periods, with the rate of change in RCI values increasing as the return period lengthened. The impact of urban river network connectivity changes on SFDC within the Changzhou urban area was more pronounced under high-magnitude storm conditions, causing a 61% reduction. Furthermore, changes in watershed river network connectivity had a larger effect on SFDC under low-magnitude storm conditions than under high-intensity storms. Over 80% of the rivers under natural connectivity conditions exhibited flood intensity severity of Level III or higher, particularly in the Chenshu–Qingyang area. The alterations in connectivity significantly decreased flood intensity severity, with 85% to 91% of rivers showing the lowest flood intensity severity of Level I. Under a 100-year rainstorm scenario, flood risk shifted from within the flood protection envelope to outside it in the Changzhou urban area. The results will provide an important scientific basis for regional flood management in plains with dense rivers.

Spatiotemporal patterns and driving factors of urban-rural water use from the production and domestic perspectives: A case study of Beijing-Tianjin-Hebei urban agglomeration, China

Water scarcity is becoming serious with economic growth, causing water competition across various sectors. Previous studies have mostly explored water use in specific sectors, yet little is known about the water reallocation between urban and rural areas. Here, we investigate urban-rural water use from the production (agriculture and industry) and domestic (urban and rural household) perspectives during 2000–2022 in the Beijing-Tianjin-Hebei urban agglomeration, and identify their potential drivers. We find that urban water use changes little due to the offset of industrial and urban domestic use, while rural water use decreases significantly with the trend of 0.387 ± 0.026 billion m3/yr. Water use changes derive from the joint effects of accelerated human activities and decelerated water use intensity. Urbanization explains more variability in water use changes than water resource endowment. Population urbanization, accompanied with rural-to-urban water reallocation, is a primary cause for enlarged urban-rural gap in water use. Urban-rural gap in water use intensity is narrowing, mainly due to the greater decline in agriculture. This study concludes that urban system often withdraws the neighbor agricultural water when the local water availability cannot meet its growing demand, and our findings offer references for regional water resource management and urban-rural environmental justice.

Climate change adaptation at the margins. The case of Cairo, Egypt

The duration, frequency and intensity of climate change are increasing. Adaptation to climate change is oftentimes perceived as a local concern. Vulnerable groups at the margins try to find nature-based ways to cope with extreme urban climate change events with diverse direct and indirect adaptive strategies in absence of government interventions. From this study's investigative approach in Cairo, Egypt we draw results preliminary from interviews with locals and observational walks in three vulnerable areas in the same urban zone. Research revealed that adaptation can be political, demanding that locals sometimes make hard choices, especially during the absence of government intervention. Nevertheless, some of the adaptive strategies observed can be promoted as mainstream sustainable nature-based adaptation. The discussion reflects some social and economic dimensions that affect local adaptation synergies. This study hopefully contributes to the understanding of how the capacity of individual homeowners can help mitigate climate change risk through the implementation of their own physical and psychological adaptive strategies. In addition, it bears relevance not only for countries sharing similar climates, economic conditions or similar social norms, but also for general adaptation strategies that might support ecosystem-based or nature-based adaptation or tailor-made scenarios for locally applicable adaptation to climate change.

A simple method to automatically remove artificial terrain from airborne LiDAR DTMs in plain areas

Alluvial plains are highly vulnerable to floods and ground disasters. Recent rapid urbanization and climate change have heightened disaster risks in urban areas. Geomorphological maps, crucial for estimating disaster risks, delineate landform boundaries based on patterns of concave breaks of slope and micro-landforms. However, enhancing the accuracy of such maps requires data extraction methods capable of capturing these features with greater precision. Traditional topographic measurements derived from adjacent elevation points in airborne light detection and ranging (LiDAR) digital terrain models (DTMs) fail to accurately represent slope variations on low ground surfaces due to the inclusion of numerous noise-like artificial terrain features. Consequently, analyzing natural terrain becomes challenging. To address this issue, our study devised a method to automatically identify and eliminate noise-like artificial terrain from LiDAR DTMs. We achieved this by removing major artificial terrain features from land-use vector data, creating an edge-preserving smooth DTM, and selectively removing and interpolating only those areas where were large differences between the smooth DTM and the LiDAR DTM. This method minimizes the interpolation of artificial terrain and quotes the LiDAR DTM for other areas, thereby minimizing the data quality loss. It is possible to identify and demarcate topographic boundaries in plains with a longitudinal gradient of approximately 1% or less at a high resolution, which can be used to investigate the relationship between flood and ground characteristics and landform volume in the plains. This method can be easily processed using only QGIS and free open data. This approach enhances the precision of disaster risk estimation and facilitates more effective urban planning in vulnerable areas.

Implementation of Norway's Food Security Policy: A Review of Strategies for Achieving Food Security in Indonesia

Food security is a global issue that is increasingly urgent to be resolved along with world population growth, urbanization, and climate change. Norway, as a developed country with an efficient and innovative agricultural system, has become an exemplary example of achieving food security. On the other hand, Indonesia still faces many challenges in achieving optimal food security. In this context, this research reviews strategies for achieving food security in Indonesia and the implementation of Norway's food security policy. The literature study method was used to collect relevant information, and the results showed that the third strategy, which focuses on "ends," is the key to increasing food security. This strategy includes increasing national food independence, developing inclusive food supply chains, and increasing resilience to climate change and natural disasters. By considering strategies that have proven effective in Norway, Indonesia can identify concrete steps to increase food security in a sustainable manner.

Land Surface Temperature Anomalies as Indicators of Urban Land Cover Change—A Study of Two Indian Cities

Rapid urbanisation over the years has led to the loss of natural land cover, thereby affecting Land Surface Temperature (LST) distribution in urban areas. This study aims to analyse LST anomalies (calculated as the deviation from the normal) over selected Indian cities and check if critical land cover changes can be identified. LST from Landsat Thermal Infrared (TIR) images acquired in March, April and May from 1988 to 2020 were used to estimate LST anomalies. Positive LST anomalies were observed mainly over barren and impervious areas; however, some areas showed a negative anomaly where the barren lands were converted to vegetated areas. The study has demonstrated that while some developed areas exhibit a positive anomaly indicative of significant changes or development, there are instances where the conversion of barren land to developed (i.e. built up) areas has resulted in a negative anomaly. Developed areas that are closer to the water creek or mangroves were associated with lower anomaly values indicating the cooling effect of the water body and vegetation. Conversely, the core urban areas generally exhibited higher LST values with positive anomalies indicating a warming effect. These findings can be used by city planners to identify hotspot areas and develop more effective strategies and policies to address the challenges of urban heat. They also highlight the regions that require infrastructural resources and policy changes to reduce the temperature.

How urban form impacts flooding

Urbanization and climate change are contributing to severe flooding globally, damaging infrastructure, disrupting economies, and undermining human well-being. Approaches to make cities more resilient to floods are emerging, notably with the design of flood-resilient structures, but relatively little is known about the role of urban form and its complexity in the concentration of flooding. We leverage statistical mechanics to reduce the complexity of urban flooding and develop a mean-flow theory that relates flood hazards to urban form characterized by the ground slope, urban porosity, and the Mermin order parameter which measures symmetry in building arrangements. The mean-flow theory presents a dimensionless flood depth that scales linearly with the urban porosity and the order parameter, with different scaling for disordered square- and hexagon-like forms. A universal scaling is obtained by introducing an effective mean chord length representative of the unobstructed downslope travel distance for flood water, yielding an analytical model for neighborhood-scale flood hazards globally. The proposed mean-flow theory is applied to probe city-to-city variations in flood hazards, and shows promising results linking recorded flood losses to urban form and observed rainfall extremes.

Slope stability assessment and landslide susceptibility mapping in the Lesser Himalaya, Mussoorie, Uttarakhand

The present study aims to assess slope stability and landslide susceptibility mapping of road-cut slopes along Mussoorie road in the Lesser Himalayan region. A total of 18 suspected unstable slope sites were selected for the investigation, and performed geo-mechanical classification techniques, including Rock Mass Rating (RMR), Slope Mass Rating (SMR), Geological Strength Index (GSI), and kinematic analysis. For the Landslide susceptibility mapping, the Frequency Ratio (FR) method was employed using the weightage of various causative factors which includes slope, aspect, curvature, elevation, distance from streams, distance from lineaments, lithology, and rainfall. The finding indicates that out of 18 selected slopes, 4 slopes are bad slope or unstable, which includes slope 3,4 and 6 in the lower part of the Mussoorie area near Jharipani, while slope 10 near Hathi Paon-Mussoorie Road is also unstable. The slopes around Junu waterfall are stable. Partially unstable slopes may vulnerable to slope failure in the future due to heavy rainfall and unstructured construction. Additionally, the Area Under Curve (AUC) and predictive rate curve values are 61% and 78% respectively, indicating acceptable overall accuracy. This study highlights the landslide issues in Mussoorie region due to rapid urbanization & climate change and demonstrates the effectiveness of the employed methods for future risk analysis.

Spatial effect of urban morphology on land surface tempature from the perspective of local climate zone

Urban expansion results in the intrusion of artificial surfaces into natural environments, giving rise to phenomena such as urban heat islands and heightened temperatures within inhabited areas. This study examined the dynamic evolution of urban morphology and land surface temperature through the lens of local climate zone. Furthermore, the spatial relationship between urban morphology indices and land surface temperature was analyzed within the context of loops. The investigation yielded several noteworthy findings: (1) LCZ8, LCZ6, and LCZD were the most significant transfer-in and transfer-out classes within the study area. (2) The heat contribution of residential LCZs (LCZ 2,3,5) decreased over time, ranging from 0.415 to 0.171, while that of industrial LCZs (LCZ 8,10) increased within the range of 0.348–0.553. (3) Urban heat island mitigation can be achieved by regulating building height and surface fraction. Establishing a judicious threshold for reducing LST is imperative for sky view factor and impervious surface fraction factors. Surface albedo exhibited a substantial inhibitory effect in 2020. The observation of urban morphological changes and long-term local climate zone considerations integrate the responsibility of mitigating urban heat islands into urban planning.

A Novel Urban Heat Vulnerability Analysis: Integrating Machine Learning and Remote Sensing for Enhanced Insights

Rapid urbanization and climate change exacerbate the urban heat island effect, increasing the vulnerability of urban residents to extreme heat. Although many studies have assessed urban heat vulnerability, there is a significant lack of standardized criteria and references for selecting indicators, building models, and validating those models. Many existing approaches do not adequately meet urban planning needs due to insufficient spatial resolution, temporal coverage, and accuracy. To address this gap, this paper introduces the U-HEAT framework, a conceptual model for analyzing urban heat vulnerability. The primary objective is to outline the theoretical foundations and potential applications of U-HEAT, emphasizing its conceptual nature. This framework integrates machine learning (ML) with remote sensing (RS) to identify urban heat vulnerability at both long-term and detailed levels. It combines retrospective and forward-looking mapping for continuous monitoring and assessment, providing essential data for developing comprehensive strategies. With its active learning capacity, U-HEAT enables model refinement and the evaluation of policy impacts. The framework presented in this paper offers a standardized and sustainable approach, aiming to enhance practical analysis tools. It highlights the importance of interdisciplinary research in bolstering urban resilience and stresses the need for sustainable urban ecosystems capable of addressing the complex challenges posed by climate change and increased urban heat. This study provides valuable insights for researchers, urban administrators, and planners to effectively combat urban heat challenges.

China's Sponge City Development: Global Position, Governance, and Potential Enhancement with Ecosystem Services

ABSTRACT China has been implementing a policy initiative termed sponge city development (SCD) since 2014 to address complex, interlinked water challenges, particularly flooding and runoff pollution, faced by urban development under climate change. Pilot implementation of the initiative in 30 selected cities provides an opportunity for learning and enhancement relevant to global practice in general and SCD expansion in particular. This article reviews China’s SCD, synthesizing: (1) SCD position in global practices for urban stormwater management; (2) governance and implementation; (3) challenges and issues in planning and management; and 4) potential enhancement with ecosystem service (ES). The article shares that: (1) China’s SCD differs from, while sharing some similarity with, global practices for urban stormwater management, particularly marked by engineering dominated implementation; (2) the policy implementation exhibits sophisticated governance in supporting the initiative; (3) there are challenges and issues concerning particularly planning and management, characterized by a lack of a systematic approach linking physical projects, ecosystem functions, societal impact, and urban development goals; and (4) an ES-based framework can deliver a systematic approach enhancing SCD beyond water resilience toward urban green transition and sustainability. This article contributes to learning about ecosystem-based integrated stormwater management during urbanization and climate change.

Within the optimal thermal range, temperature fluctuations with similar means have little effect on offspring phenotypes: A comparison of two approaches that simulate natural nest conditions

Temperature influences nearly every aspect of organismal function. Because aspects of global change such as urbanization and climate change influence temperature, researchers must consider how altering thermal regimes will impact biodiversity across the planet. To do so, they often measure temperature in natural and/or human-modified habitats, replicate those temperatures in laboratory experiments to understand organismal responses, and make predictions under models of future change. Consequently, accurately representing temperature in the laboratory is an important concern, yet few studies have assessed the consequences of simulating thermal conditions in different ways. We used nest temperatures for two urban-dwelling, invasive lizards (Anolis sagrei and A. cristatellus) to create two egg incubation treatments in the laboratory. Like most studies of thermal developmental plasticity, we created daily repeating thermal fluctuations; however, we used different methods to create temperature treatments that differed in the magnitude and breadth of thermal cycles, and then evaluated the effects of these different approaches on embryo development and hatchling phenotypes. Additionally, we measured embryo heart rate, a proxy for metabolism, across temperature to understand the immediate effects of treatments. We found that treatments had minimal effect on phenotypes likely because temperatures were within the optimal thermal range for each species and were similar in mean temperature. We conclude that slight differences in thermal treatments may be unimportant so long as temperatures are within a range appropriate for development, and we make several recommendations for future studies of developmental plasticity.